>> right. he figured she was with us or with her mom. >> reporter: hunter, who's living with her, doesn't say anything, doesn't call you? doesn't sound the alarm and call anybody? >> don't get me started. >> reporter: mark and anna continued to work the phones. eventually reaching christina's pal, steven nickerson. >> her dad had asked me if he had seen -- if i had seen christina or heard from christina. and i said, "no, and the last time i talked to her was, you know, saturday morning." and he asked me, like "who'd she leave with, and i told him it was enrique. >> and i'm like, "who's enrique?" >> yeah, because we didn't know enrique. >> reporter: enrique arochi was a guy christina had known in school. he was the one who left the party at the same time and had offered to walk with her. >> how well did you know enrique? >> i graduated high school with him but i wasn't -- i was acquaintances with him. i didn't really ever talk to him. >> and that was pretty much christina's relationship with him, too, right? >> yeah. >> reporter: steven chased down enrique's number from other